Various data processing systems have been developed including storage systems, cellular telephone systems, and radio transmission systems. In such systems, data is transferred from a sender to a receiver via a storage media. For example, in a storage system, data is sent from a sender (e.g., a write function) to a receiver (e.g., a read function) via a storage media. As information is stored and transmitted in the form of digital data, errors are introduced that, if not corrected, can corrupt the data and render the information unusable. The effectiveness of any transfer is impacted by any losses in data caused by various factors.
Storage systems, such as disk drives, typically include one or more disks (e.g., magnetic disks or other storage media). Data is stored on the disks as a series of concentric tracks each comprising a number of data sectors. Each data sector is formatted to include a preamble, a sync mark (e.g., syncMark), and a data field. The storage system includes a read channel that processes the acquisition preamble to adjust the magnitude of the read signal and synchronize timing recovery in sampled amplitude read channels so that it can accurately read the data field. The sync mark demarks the beginning of the data field. A sync mark detector within the read channel detects the sync mark, and enables operation of a channel decoder to begin decoding the detected data sequence. When the sync mark detector is unable to detect the sync mark, the read channel cannot synchronize to the data field. For example, the sync mark detector could miss detecting the sync mark due to signal defects where the read-back signal on the sync mark is destroyed or distorted beyond the tolerance of the sync mark detector. When this happens, the read channel will recognize that the sync mark was not detected by the sync mark detector and initiate a retry. The storage system will wait for the disk to complete a revolution, which increases the overall access time, and again attempt to accurately detect the sync mark. When the sync mark detector cannot detect the sync mark upon retry, a channel fault can occur and data from the sector could be lost.